1. Field of the Invention
The present invention relates to a method for wireless communication, and, more particularly, to a method for wireless communication with increased performance and reliability within a vehicle.
2. Description of the Related Art
It is known for wireless communication to be established between various systems within a vehicle, such as an automobile, and external applications such as an internet search engine, for example. Attaining reliable wireless communication with a vehicle is problematic, however, because wireless communication is deeply affected by the quality of the wireless signals as received by the vehicle as it travels toward and away from various base stations. The quality of the signals received by the vehicle is highly dependent upon the distance between the vehicle and the nearest transmitting base station as well as on the level of traffic on the communication channel between the vehicle and the base station.
The handoff process is always one of the major challenges in providing pervasive and ubiquitous mobile wireless services. Handoff is defined as the transfer of radio resources from a previously used base station to a new base station. Normally handoff is carried out when the reception from the current base station is below a certain threshold as illustrated in FIG. 1. A client vehicle may travel in direction 11. The level of signal power from base stations A and B as received at the client vehicle is shown as PrxA and PrxB, respectively. Base station A may have an area of coverage indicated by 16A, and base station B may have an area of coverage indicated by 16B. When the level of signal power from base station A falls below a threshold power level Pth (i.e., PrxA<Pth), as at 12, then handoff is initiated. The actual handoff may occur at 14.
Depending on the technology used, handoff may be of either the hard type or the soft type. A hard handoff (also known as break before make) involves releasing current resources before acquiring the new ones. This hard type of handoff is common with Time Division Multiple Access (TDMA)/Frequency Division Multiple Access (FDMA) based technologies, though new generation cellular systems have mitigated this issue to some extent. A soft handoff (also known as make before break), on the other hand, involves establishing communication with a new base station while still maintaining the old base station. This soft type of handoff is very common for Code Division Multiple Access (CDMA) based systems.
Current solutions for transferring resources from an old base station to the new one are not sufficient to provide the required Quality of Service (QoS) for continuous streaming applications. The present invention provides several methods of using location based information to assist the handoff process and thereby enhance the overall network performance for all applications.
What is neither disclosed nor suggested in the art is a method for mobile wireless communication that overcomes the above-mentioned problems and disadvantages. More specifically, what is neither disclosed nor suggested in the art is a method for mobile wireless communication in which handoffs can be planned based on information pertaining to the expected route to be taken by the vehicle to its destination. That is, the prior art does not disclose or suggest using vehicle route information proactively rather than reactively to assist handoffs in wireless networks.